The performance of a communication network such as a cellular network is affected by factors such as the data and voice traffic load, the RF coverage, the level of inter-cell interference, the location of user devices and hardware failures. Data such as throughput and delay can be collected and aggregated for a group of user devices at the network level to monitor the performance of the network. However, monitoring the performance of an individual user device is more problematic. For example, the performance of an individual user device can vary more frequently and unpredictably compared to the performance of a group of user devices. Techniques used for monitoring performance and detecting anomalies at the group level may be less effective than at the level of an individual user device.